The present invention relates to a measuring device for a heat exchanger which has a pressure tube arrangement spaced apart by bars and having a combustion side and an isolation side. The invention also relates to a method for determining heat flows at a pressure tube arrangement, a heat exchanger having a measuring device, and the use of a measuring device for measuring the heat flow.
It is known in the prior art for the pressure tube arrangements, which as a rule form integral parts of heat exchangers or heat exchanger walls, to be monitored with regard to the heat flux taking place therein. Thus, for example, a heat flux measuring device for pressure tubes and a method for measuring a heat flux through pressure tubes is known from WO 2004/036116 A2. The heat flux sensors described therein are formed as an integral part of the pressure tubes. On account of the high costs, however, it is desirable in practice to reduce the number of heat flux sensors required. As a result, however, gaps in the monitoring of the heat flux at the pressure tube arrangements could arise, and so deposits possibly occurring in these gaps cannot be recognized in good time and removed.